NASA engineers are evaluating the loss of a large piece of insulation foam from the Space Shuttle Discovery's external fuel tank during Tuesday's launch. Based on initial assessments, the foam -- which appears to measure approximately 24 to 33 inches long, 10 to 13 inches wide and 2-1/2 to 8 inches thick -- was seen by high-resolution camera equipment added to the Shuttle system after the loss of Columbia in 2003. The accident was caused by foam from the external tank hitting the orbiter during launch.

There was no indication the piece of foam sighted Tuesday caused any damage to Discovery. The Shuttle will undergo further inspection beginning Thursday to check for any significant damage to the orbiter.

"As with any unexpected occurrence, we will closely and thoroughly evaluate this event and make any needed modifications to the Shuttle before we launch again," NASA Administrator Michael Griffin said. "We have said repeatedly that the first two flights in our Return to Flight sequence are test flights. Among the things we are testing are the integrity of the foam insulation and the performance of new camera equipment installed to detect problems. The cameras worked well. The foam did not."

Discovery's seven crew members are being updated with the latest ground team analysis of the foam loss and are continuing to take part in the inspection process.